The inventive subject matter relates to power systems and, more particularly, to data center power systems.
Data centers typically utilize redundant power systems. Commonly, one or more uninterruptible power supplies (UPSs) may be used to provide power from a primary utility source, with redundant (i.e., backup, auxiliary) power being provided by the UPS from a secondary source, such as a battery. An automatic transfer switch (ATS) may be used to switch between the primary utility source and a local diesel-powered motor/generator set. Responsive to a failure of a primary utility source, equipment in the data center may be temporarily powered by the UPS from the battery until the utility source is restored. In the event that the outage of the utility source is extended, the local generator may be started and the ATS may transfer the load to the generator until the utility service is restored. Some data centers also utilize additional sources, such as flywheels, photovoltaic panels, and fuel cells.